One known method for controlling the supercharging pressure of an internal combustion engine is described in European Patent No. 0 323 754 B1. In accordance with the described method, an acquired actual supercharging pressure value is compared to an auxiliary value, which is smaller than a set-point value. While the actual value is less than the auxiliary value, a device specifying the rate of increase of the supercharging pressure is triggered to stipulate the maximum increase rate of the supercharging pressure. The value of the maximum increase rate can depend on the measured actual increase rate of the charge-air pressure, on the gear speed that is set, or on the temperature of the intake air.
A device for controlling the supercharging pressure of an internal combustion engine with a turbocharger is described in German Patent 33 03 350 A1. The disclosed control device includes an open-loop control system and a closed-loop control system. A desired supercharging pressure is roughly adjusted by the open-loop control system by a control unit that adjusts the supercharging pressure. The control unit that adjusts the supercharging pressure is set for one manipulated variable based on empirically determined values. The closed-loop control system then corrects the supercharging pressure adjusted by the open-loop control system to reduce deviations of the adjusted supercharging pressure from the desired supercharging pressure.
A fuel-regulating device for gas-turbine engines is described in German Patent 19 02 356 B2. This regulating device has a proportional, integral, differential ("PID") action response. The weighting of the proportional, integral, and differential components according to specific functions is variable and depends upon the rotational frequency of the engine. No parameters, other than rotational frequency, are used in the weighting of the components.
The object of the present invention is to render possible optimal automatic control of the supercharging of an internal combustion engine. Above and beyond that, an object is to minimize the complexity of the supercharging control system. These and other objects are solved by the system and method of the invention described below.